Extracting method, structure and apparatus, and separating method, structure and apparatus

ABSTRACT

Disclosed herewith is an extracting structure for incorporating a substance contained in a first liquid into a second liquid. The extracting structure comprises: a channel for allowing the first liquid and the second liquid to flow therein in a form of a layered flow in which first laminar flows of the first liquid and second laminar flows of the second liquid alternately come in contact with each other, wherein the substance in the first laminar flow of the first liquid moves to the second laminar flow of the second liquid through the boundaries between the first laminar flows and the second laminar flows; and a separating section, connected to a lower stream side of the channel, for separating the second liquid from the first liquid. Further, disclosed also herewith is a separating structure for separating a second liquid from the mixture of a first liquid and the second liquid.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is based on Japanese Patent Application No.2001-168047 filed in Japan on Jun. 4, 2001, the entire content of whichis hereby incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to an extracting method, anextracting apparatus, a separating method and a separating apparatus.The invention relates to a technique for selectively extracting anobject contained in a liquid.

[0004] 2. Description of the Related Art

[0005] In recent years, dioxin or the like generated from garbageincinerators and the like is recognized as serious environmentalproblem, and it is an important problem to measure and manage adischarge density of the dioxin. Currently, a method of measuring adensity of the dioxin or the like is defined by Japanese IndustrialStandards (JIS).

[0006] In the case where the dioxin or the like is measured, in order toextract the dioxin contained in water, similarly to a conventionalsolvent extracting method, water and an organic solvent are put into aseparating funnel or the like and are shaken to be mixed, the dioxin inthe water is incorporated into the organic solvent and only the organicsolvent is extracted so as to be separated from the water.

[0007] However, this method requires a lot of solvent, long time and alot of costs.

[0008] Recently, an attention is paid to μ-TAS (μ-Total Analysis System)which refines chemical analysis and synthesizing apparatuses andchemical analysis and synthesizing methods using a micromachinetechnique. The μ-TAS, which is refined more finely as compared withconventional apparatuses, has the merits such that an amount of samplesis small, reacting time is short and an amount of refuse is small. Inthe case where the μ-TAS is adapted to the environment measuring fieldor the like, it has the merits that usage of reagent and organic solventis small and reacting time (measuring time) is short, and further sincean apparatus is small, the measurement can be made on the ground, sothat the immediacy of an inspection is expected to be improved.

[0009] However, conventionally a technique for extracting a solventusing a micro fluid system to which the micromachine technique isapplied has not been found.

[0010] For example, in a very narrow channel having a width of severaldozen to several hundred μm, the viscosity of a liquid is dominant, andit is difficult to stir and mix liquids. For this reason, in order toincorporate the dioxin contained in the water into the organic solvent,it is inefficient to stir water and organic solvent in a channel.

[0011] In addition, it is desirable that only an organic solvent isextracted from a small amount of mixed water and organic solvent in amicroarea and to separate it from the water.

SUMMARY OF THE INVENTION

[0012] Therefore, a first technical problem to be solved by theinvention is to provide an extracting method, an extracting apparatusand a chip for the extracting apparatus which incorporate a substancecontained in a first liquid into a second liquid efficiently in amicroarea.

[0013] In addition, a second technical problem to be solved by thepresent invention suggests a separating method, a separating apparatusand a chip for the separating apparatus which separate a second liquidfrom mixed first liquid and second liquid in a microarea.

[0014] In order to solve the first technical problem, the presentinvention provides an extracting method which is basically characterizedin that a layered first liquid and a layered second liquid come incontact with each other, and a substance in a first laminar flow of thefirst liquid is moved into a second laminar flow of the second liquid.More concretely, the following extracting method is provided.

[0015] The extracting method is to incorporate the substance containedin the first liquid into the second liquid so as to extract thesubstance. This extracting method has the first step and the secondstep. In the first step, the first liquid and the second liquid aretransferred into a channel so as to alternately come in contact witheach other respectively in not less than one or two laminar state, andthe substance in the first laminar flow of the first liquid is moved tothe second laminar flow of the second liquid. In the second step, thesecond liquid is separated from the first liquid in a lower stream sideof the channel.

[0016] In the first step, the first fluid and the second fluid areallowed to flow into the channel with a very small width so as to be inthe laminar state. When two or more first laminar flows and the secondlaminar flows exist, the first laminar flows and the second laminarflows are arranged alternately so as to come in contact with each other.

[0017] Generally the substance in the liquid diffuses voluntarily.Namely, molecules of a medium (liquid) continually collide with smallmatters (particles of the substance) in the medium, and the smallmatters move irregularly in the medium. Due to this Brownian movement,the small matters diffuse in the medium. A relative interfacial area ofthe liquid becomes large in the microarea (namely, a surface areabecomes wider as compared with a volume), and the diffusion speedbecomes abruptly high. For this reason, the particles of the substancein the first laminar flow move to the second laminar flow quickly.Namely, the particles are incorporated into the second liquid. In thiscase, it is preferable that the particles of the substance difficultlyreturn from the second laminar flow to the first laminar flow, and forexample, it is preferable that the substance is easily incorporated intothe second liquid easier than into the first liquid. When the substanceis dioxin or the like, the first fluid can be water and the second fluidcan be an organic solvent. Moreover, in order to diffuse it efficiently,it is preferable that a flow velocity of the first laminar flow is equalwith a flow velocity of the second laminar flow and the flow velocitiesdo not relatively differ.

[0018] According to the above method, the flow of the laminar flow andthe particle diffusion phenomenon in the channel are used, so that thesubstance contained in the first liquid can be incorporated into thesecond liquid efficiently in the microarea.

[0019] In the first step, even if the liquids are sequentiallytransferred, the liquids may be stopped in the middle of the channel.

[0020] In the second step, only the second liquid is collected, so thatthe substance contained in the first liquid can be extracted.

[0021] Preferably at the first step, a width of one laminar flow is notmore than 50 μm. When the width is not more than 50 μm, a Reynoldsnumber becomes small, and the liquid is easily transferred in thechannel in the laminar state.

[0022] The second step can collect only the second liquid in thefollowing various forms.

[0023] Preferably, the second step includes a channel branching step. Inthe channel branching step, in the lower stream side of the channel, thefirst laminar flow is allowed to flow into a first branch channel, andthe second laminar flow is allowed to flow in a second branch channel.In this case, the channels is branched for each liquid in the laminarstate, so that the second liquid can be separated from the first liquideasily.

[0024] Preferably, the second step includes a charging step. In thecharging step, a vicinity of an inlet of the first branch channel or thesecond branch channel is charged. Polarity is provided to the firstliquid or the second liquid and the other liquid has no polarity by thecharging step, one liquid having a polarity is activated so as to enterthe charged first branch channel or second branch channel, and thus theliquids can be separated more efficiently. For example, nonpolarmolecules such as petroleum ether, carbon tetrachloride, benzene,xylene, nitrobenzene and iodine can be separated from water havingpolarity. As for a mixed liquid composed of three or more liquids, inthe case where only one liquid has polarity or where only one liquid isnonpolar, the one liquid can be separated from the other liquids.

[0025] In addition, the present invention provides the followingseparating method in order to solve the second technical problem.

[0026] The separating method separates a second liquid from mixed firstliquid and second liquid. The separating method has the first step andthe second step. In the first step, the mixed first liquid and secondliquid are allowed to flow into the channel. The channel is composed ofa first space and a second space. The first space is provided with amicrostructure, and one of the first liquid and the second liquid easilyflows relatively. The second space extends along the first space and isconnected with the first space. In the second step, the second liquid iscollected in a lower stream side of the first space or the second spacein which the second liquid flows.

[0027] According to the above method, when the mixed first and secondliquids are allowed to flow in the channel, one of the first and secondliquids which easily flow relatively into the first space flows in thefirst space, and the other liquid flows in the second space. Forexample, the structures undergo a hydrophilic treatment and are providedwith a suitable functional group, so that one of the first and secondliquids can easily flow relatively in the first space. Since the firstliquid and the second liquid separate from each other and the secondliquid flows in the first space or the second space, the second liquidcan be collected in the lower stream.

[0028] Therefore, the second liquid can be separated from the mixedfirst and second liquids in the microarea.

[0029] In the above method, the microstructure is constituted suitably,so that one of the first and second liquids can be allowed to easilyflow relatively in the first space of the separated channel. Forexample, the microstructure contains a lot of elements, and a distance(gap) between the adjacent elements is not more than 10 μm. Themicrostructure may be made of a porous substance in which microholes areopened on all sides, or a fiber block.

[0030] Preferably, the structure is a column-shaped structure whichextends from the first space side to the second space side.

[0031] A fluid which difficultly flows relatively in the first space ofthe first liquid and the second liquid can move easily along theextending direction of the microstructure towards the second space.Therefore, a separating efficiency of the liquid can be heightened.

[0032] More preferably, one of the first liquid and second liquidcontains water. The above structure undergoes a water-repellenttreatment. In this case, the first or second liquid containing waterrepels the microstructure which underwent the water-repellent treatmentso as to move to the second space, so that the liquid separatingefficiency can be heightened. In the case where only one liquid of amixed liquid composed of three or more liquids has water and affinity,the one liquid can be separated from the other liquids.

[0033] Further, in order to solve the above first technical problem, thepresent invention provides an extracting apparatus which is basicallycharacterized in that a first liquid space in which a first liquid is toflow in a layered state and a second liquid space in which a secondliquid is to flow in a layered state are arranged so as to come incontact with each other in the layer direction. More concretely, theextracting apparatus is constituted in the following manner.

[0034] The extracting apparatus incorporates a substance contained inthe first liquid into the second liquid and extract the substance. Theextracting apparatus has a channel and a separating section. The firstliquid and the second liquid flow in the channel with them contactingalternately in not less than one or two laminar state, and the substancein the first laminar flow of the first liquid moves to the secondlaminar flow of the second liquid. The separating section is connectedto a lower stream side of the channel and separates the second liquidfrom the first liquid.

[0035] According to the above constitution, the first fluid and thesecond fluid are allowed to flow in a very small width of the channel soas to be capable of being in a laminar state. In the case of two or morefirst and second laminar flows, the first laminar flows and the secondlaminar flows are arranged alternately so as to come in contact witheach other.

[0036] Generally, the substance in the liquid diffuses voluntarily.Namely, molecules of a medium (liquid) continually collide with smallmatters (particles of the substance), and the small matters move in themedium irregularly. Due to this Brownian movement, the small mattersdiffuse in the medium. In the microarea, the relative interfacial areaof the liquid becomes large (namely, a surface area becomes larger ascompared with a volume), and the diffusion speed becomes abruptly high.For this reason, the particles of the substance in the first laminarflow move to the second laminar flow quickly. Namely, the particles areincorporated into the second liquid. In this case, it is preferable thatthe particles of the substance difficultly return from the secondlaminar flow to the first laminar flow, and for example, it ispreferable that the substance is incorporated into the second liquidmore easily than into the first liquid. When the substance is dioxin orthe like, the first fluid can be water and the second fluid can be anorganic solvent. Moreover, in order to diffuse the substanceefficiently, it is preferable that the flow velocity of the firstlaminar flow is equal with the flow velocity of the second laminar flowand the flow velocities do not vary relatively.

[0037] According to the above constitution, the flow of the laminar flowand the diffusion phenomenon of the particles in the channel are used,so that the substance contained in the first liquid can be incorporatedinto the second liquid efficiently in the microarea.

[0038] In the separating section, only the second liquid is collected,so that the substance contained in the first liquid can be extracted.

[0039] Preferably, in the channel, a width of one laminar flow is notmore than 50 μm. When the width is not more than 50 μm, a Reynoldsnumber becomes small, and the liquid can be easily transferred in thelaminar state in the channel.

[0040] The separating section can collect only the second liquid in thefollowing various forms.

[0041] Preferably the separating section includes a first branch channelin which the first laminar flow flows, and a second branch channel inwhich the second laminar flow flows. In this case, the channel isbranched for each liquid in the laminar state, so that the second liquidcan be separated from the first liquid easily. More preferably, acharging section, which charges a vicinity of an inlet of the firstbranch channel or the second branch channel is provided.

[0042] According to the above constitution, in the case where the firstliquid or the second liquid has polarity and the other one is nonpolar,one liquid having polarity is activated so as to enter the charged firstbranch channel or second branch channel, so that the liquid can beseparated more efficiently. For example, nonpolar molecules such aspetroleum ether, carbon tetrachloride, benzene, xylene, nitrobenzene andiodine can be separated from water having polarity. As for a mixedliquid composed of three or more liquids, in the case where only oneliquid has polarity or where only one liquid is nonpolar, the one liquidcan be separated from the other liquids.

[0043] Further, in order to solve the above second technical problem,the present invention provides a separating apparatus having thefollowing constitution.

[0044] The separating apparatus separates the second liquid from themixed first liquid and second liquid. The separating apparatus has afirst space, a second space and a discharge port. The first space isprovided with a microstructure, and one of the first liquid and thesecond liquid easily flows relatively. The second space extends alongthe first space and is connected to the first space. The discharge portis connected to a lower stream side of the first space or the secondspace where the second liquid flows, and the second liquid flowstherein.

[0045] According to the above constitution, when the mixed first andsecond liquids are allowed to flow in the first space and the secondspace, one of the first liquid and the second liquid which easily flowsrelatively in the first space flows in the first space, and the otherliquid flows in the second space, so that the first liquid and thesecond liquid are separated from each other. For example, the structuresundergo a hydrophilic treatment or a suitable functional group isprovided, so that one of the first liquid and the second liquid can beallowed to easily flow in the first space relatively. Since the secondliquid flows one of the first space or the second space, the secondliquid can be collected from the discharge port. Therefore, the secondliquid can be separated from the mixed first liquid and the secondliquid in the microarea.

[0046] In the above constitution, the microstructure is suitablyconstituted, so that one of the first liquid and the second liquid canbe allowed to easily flow in the first space of the separated channelrelatively. For example, the microstructure includes a lot of elements,and a distance (gap) between the adjacent elements is not more than 10μm. The microstructure may be composed of a porous substance in whichmicroholes are opened on all sides, or a fiber block.

[0047] Preferably, the structure is a column-shaped structure whichextends from the first space side to the second space side.

[0048] A fluid which difficultly flows relatively in the first space ofthe first liquid and the second liquid can move easily along theextending direction of the microstructure towards the second space.Therefore, a separating efficiency of the liquid can be heightened.

[0049] More preferably, one of the first liquid and second liquidcontains water. The above structure undergoes a water-repellenttreatment.

[0050] According to the above constitution, the first or second liquidcontaining water repels the microstructure which has undergone thewater-repellent treatment so as to move to the second space, so that theliquid separating efficiency can be heightened. In the case where onlyone liquid of a mixed liquid composed of three or more liquids has waterand affinity, the one liquid can be separated from the other liquids.

[0051] Further, in order to solve the above first technical problem, thepresent invention provides a chip for the extracting apparatus havingthe following constitution.

[0052] The chip to be used for the extracting apparatus is used for theextracting apparatus which incorporates the substance contained in thefirst liquid into the second liquid so as to extracts the substance. Thechip has a channel. The first liquid and the second liquid aretransferred in the channel so as to come in contact with each otheralternately in not less than one or two laminar state, and the substancein the first laminar flow of the first liquid can be moved into thesecond laminar flow of the second liquid.

[0053] In the above constitution, the first fluid and the second fluidare allowed to flow in a very small width of the channel so as to becapable of being in the laminar state. In the case of two or more firstlaminar flows and second laminar flows, the first laminar flows and thesecond laminar flows are arranged alternately so as to be capable ofbeing in contact with each other.

[0054] Generally, the substance in the liquid diffuses voluntarily.Namely, molecules of a medium (liquid) continually collide with smallmatters (particles of the substance) in the medium, and the smallmatters move in the medium irregularly. Due to this Brownian movement,the small matters diffuse in the medium. In the microarea, the relativeinterfacial area of the liquid becomes large (namely, a surface areabecomes larger as compared with a volume), and the diffusion speedbecomes abruptly high. For this reason, the particles of the substancein the first laminar flow move to the second laminar flow quickly.Namely, the particles are incorporated into the second liquid. In thiscase, it is preferable that the particles of the substance difficultlyreturns from the second laminar flow to the first laminar flow, and forexample, it is preferable that the substance is incorporated into thesecond liquid more easily than into the first liquid. When the substanceis dioxin or the like, the first fluid can be water and the second fluidcan be an organic solvent. Moreover, in order to diffuse the substanceefficiently, it is preferable that the flow velocity of the firstlaminar flow is equal with the flow velocity of the second laminar flowand the flow velocities do not vary relatively.

[0055] According to the above constitution, the flow of the laminarflows and the diffusion phenomenon of the particles in the channel areused, so that the substance contained in the first liquid can beincorporated into the second liquid efficiently in the microarea.

[0056] Only the second liquid is collected, so that the substancecontained in the first liquid can be extracted.

[0057] Preferably, in the channel, a width of one laminar flow is notmore than 50 μm. When the width is not more than 50 μm, a Reynoldsnumber becomes small, and the liquid can be easily transferred in thelaminar state in the channel.

[0058] Preferably, a first branch channel and a second branch channelare provided. The first branch channel is connected to a lower streamside of the channel, and the first laminar flow flows therein. Thesecond branch channel is connected to a lower stream side of thechannel, and the second laminar flow flows therein. According to theabove constitution, the channel is branched for each liquid in thelaminar state, so that the second liquid can be separated from the firstliquid easily. More preferably, a charging section, which charges avicinity of an inlet of the first branch channel or the second branchchannel is provided.

[0059] According to the above constitution, in the case where the firstliquid or the second liquid has polarity and the other one is nonpolar,one liquid having polarity is activated so as to enter the charged firstbranch channel or second branch channel, so that the liquid can beseparated more efficiently. For example, nonpolar particles such aspetroleum ether, carbon tetrachloride, benzene, xylene, nitrobenzene andiodine can be separated from water having polarity. As for a mixedliquid composed of three or more liquids, in the case where only oneliquid has polarity or where only one liquid is nonpolar, the one liquidcan be separated from the other liquids.

[0060] Further, in order to solve the second technical problem, thepresent invention provides a chip for the separating apparatus havingthe following constitution.

[0061] The chip for the separating apparatus is used for the separatingapparatus which separates a second liquid from mixed first liquid andsecond liquid. The chip has a first space, a second space and adischarge port. The first space is provided with a microstructure, andone of the first liquid and the second liquid easily flows relatively.The second space extends along the first space and is connected to thefirst space. The discharge port is connected to a lower stream side ofthe first space or the second space where the second liquid flows, andthe second liquid flows therein.

[0062] According to the above constitution, when the mixed first andsecond liquids are allowed to flow in the channel, one of the firstliquid and the second liquid which easily flows relatively in the firstspace flows in the first space, and the other liquid flows in the secondspace. For example, the structure undergoes a hydrophilic treatment or asuitable functional group is provided, so that one of the first liquidand the second liquid can be allowed to easily flow in the first spacerelatively. Since the first liquid and the second liquid are separatedfrom each other and the second liquid flows in one of the first spaceand the second space, the second liquid can be collected on the lowerstream side.

[0063] Therefore, the second liquid can be separated from the mixedfirst liquid and the second liquid in the microarea.

[0064] The microstructure is suitably constituted, so that one of thefirst liquid and the second liquid can be allowed to easily flow in thefirst space relatively. For example, the microstructure includes a lotof elements, and a distance (gap) between the adjacent elements is notmore than 10 μm. The microstructure may be composed of a poroussubstance in which microholes are opened on all sides, or a fiber block.

[0065] Preferably, the structure is a column-shaped structure whichextends from the first space side to the second space side.

[0066] According to the above constitution, a fluid which difficultlyflows relatively in the first space of the first liquid and the secondliquid can move easily along the extending direction of themicrostructure towards the second space. Therefore, a separatingefficiency of the liquids can be heightened.

[0067] More preferably, one of the first liquid and second liquidcontains water. The above structure undergoes a water-repellenttreatment.

[0068] According to the above constitution, the first or second liquidcontaining water repels the microstructure which has undergone thewater-repellent treatment so as to move to the second space, so that theliquid separating efficiency can be heightened. In the case where onlyone liquid of a mixed liquid composed of three or more liquids has waterand affinity, the one liquid can be separated from the other liquids.

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] These and other objects, advantages and features of the inventionwill become apparent from the following description thereof taken inconjunction with the accompanying drawings in which:

[0070]FIG. 1 is a schematic diagram showing a flow of a microarea;

[0071]FIG. 2 is a schematic diagram showing movement of particles in themicroarea;

[0072]FIG. 3 is a graph showing a relationship among a channel width, arelative interfacial area and a diffusion speed;

[0073]FIG. 4 is a main section perspective view of a pretreatmentassembly according to a first embodiment of the present invention;

[0074]FIG. 5 is an exploded perspective view of the pretreatmentassembly;

[0075]FIG. 6 is a top view of the pretreatment assembly;

[0076]FIG. 7 is a main section exploded perspective view of thepretreatment assembly according to a second embodiment of the presentinvention;

[0077]FIG. 8 is a main section enlarged perspective diagram of thepretreatment assembly;

[0078]FIG. 9 is a structural diagram of divided channels according to amodified example; and

[0079]FIG. 10 is a flowchart of the pretreatment step in a dioxinmeasurement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0080] There will be explained below embodiments of the presentinvention with reference to FIGS. 1 to 10.

[0081] Firs of all, a first embodiment of the present invention will beexplained with reference to FIGS. 1 to 6 and FIG. 10.

[0082]FIG. 1 typically shows a flow of water and solvent in a microarea.Divided channels 10 a and 10 b, which are divided respectively intoplural channels 13 a to 13 g and 15 a to 15 g by partition walls 12 and14, are formed on both ends of one center channel 10 without a partitionso as to be opposed to each other. The solvent and the water flowalternately in one divided channel 10 a. For example, the solvent flowsin the channels 13 a, 13 c, 13 e and 13 g and the water flows in thechannels 13 b, 13 d and 13 f. A width of the respective channels 13 a to13 g is, for example, 20 μm, and since a Reynolds number becomes smallin such a microarea, the water and the solvent outflow from the dividedchannel 10 a become laminar flows 11 a and 11 b respectively in thecenter channel 10, and if they are adjacent to each other, they flowwithout mixing, and interfaces 11 c are formed respectively between thewater and the solvents. The laminar flows 11 a and 11 b flow into thechannels 15 a to 15 g of the other divided channel 10 b. Namely, thesolvent flows into the channels 15 a, 15 c, 15 e and 15 g, and the waterflows into the channels 15 b, 15 d and 15 f.

[0083]FIG. 2 typically shows movement of particles 16 a and 16 b ofdioxin or the like in the liquid. In the divided channel 10 a, theparticles 16 a are contained only in the water which flows in thechannels 13 b, 13 d and 13 f but are not contained in the solvent whichflows in the channels 13 a, 13 c, 13 e and 13 g. Just after outflowingto the center channel 10, the particles 16 a are contained in waterlayers 11 a. The particles 16 a voluntarily diffuse in the liquid due toBrownian movement. At this time, as shown by arrows 17, the particles 16b which exceed interfaces 11 c and moves from the water layers 10 d tosolvent layers 10 b hardly returns to the water layers 10 d due to adifference of solubility. Since a relative interfacial area of theliquid becomes large in the microarea and a diffusion speed abruptlybecomes high, the particles 16 a in the water layers 11 a move to thesolvent layers 11 b quickly. Therefore, if only the solvent layers 11 bare collected by using the divided channel 11 b, the particles 16 b canbe extracted.

[0084]FIG. 3 is one example of a graph of the channel width, therelative interfacial area S/V and the diffusion speed t. When thechannel width becomes smaller than 50 μm, the diffusion time S abruptlybecomes short and the diffusion speed becomes high. Therefore, when thechannel width is not more than 50 μm, preferably not more than 20 μm,the mixing and extracting time can be shortened greatly. For example,this embodiment can be used in a blood clotting test which requires thata reagent should be mixed fast (within 1 second).

[0085] FIGS. 4 to 6 show an embodiment in which the present invention isapplied to a pretreatment assembly 50 for measuring dioxin.

[0086] As shown in FIG. 4(a), in order to allow a condensed dioxinsolution and an organic solvent to flow into a layer form, channels 20and 30 which cross three dimensionally are formed.

[0087] The organic solvent flows in the channel 20 arranged in an uppersection to a direction shown by an arrow 28. As for the channel 20, onemain channel 21 branches into three branch channels 22 on a lower streamside, and drum-shaped down channels 24 are formed to face downwardrespectively from bottom faces of end sections 23 of the branch channels22.

[0088] The condensed dioxin solution flows in an upper stream channel 31of the channel 30 arranged in a lower section to a direction shown by anarrow 38. Divided channels 32 are formed in the middle way of thechannel 30, and the organic solvent and the dioxin solution respectivelyflow in channels 34 and 35 which are formed alternately. Namely, pluralpairs of partition walls 33 a are arranged with an interval. Therespective paired partition walls 33 a extend to the channel directionand have a thickness of a several μm. Upper stream sides of the pairedpartition walls 33 a are combined by connecting walls 33 b. The organicsolvent flows from the down channels 24 to the channels 34 between thepaired partition walls 33 a, and the condensed dioxin solution flowsfrom the upper stream channel 31 to the channels 35 between the pairedadjacent partition walls 33 a.

[0089] One laminar flow mixing channel 36 is formed on the lower streamside of the divided channels 32, and the dioxin solution and the organicsolvent flow in the laminar state in the laminar flow mixing channel 36so that the dioxin dissolves in and is incorporated into the organicsolvent layer. A width of the laminar flow mixing channel 36 is about200 μm, and its height (up-and-down direction in the diagram) is about100 μm.

[0090] Meanwhile, as shown in FIG. 4(b), divided channels 40 are formedon the lower stream side of the laminar flow mixing channel 36 so as tobe opposite to the divided channels 32, and the water and the organicsolvent respectively flow in channels 44 and 45 formed alternately.

[0091] Namely, plural pairs of partition walls 41 a are arranged with aninterval. The respective paired partition walls 41 a extend to thechannel direction, and their lower stream sides are combined byconnecting walls 41 b. The organic solvent containing dioxin flows intothe channels 44 between the paired partition walls 41 a, and the waterfrom which the dioxin is removed flows in the channels 45 between thepaired adjacent partition walls 41 a.

[0092] Discharge channels 42 are formed on the lower stream side of thepaired partition walls 41 a, and as shown by arrows 43, the organicsolvent containing the dioxin is sucked downward and treated at the nextstep.

[0093] Meanwhile, after the water from which the dioxin is removedpasses through the divided channel 40, it flows in a channel 46 and, asshown by an arrow 48, is sucked upward from an end section 47 of thechannel.

[0094] The channels 20 and 30 are formed in the pretreatment assembly 50in a manner that a plurality of chips 51 to 60, shown in FIG. 5, arelaminated. In this specification, the pretreatment assembly 50 may bementioned as a chip.

[0095] The respective chips 51 to 60 can be created accurately, forexample, by dry-etching silicon or glass using ICP (Inductively CoupledPlasma). Direct coupling is used for silicon-to-silicon coupling, andanode coupling is used for silicon-to-glass coupling, but the bondingmay be carried out by epoxy adhesive. Moreover, a mold of the chip isformed by galvanoplasty using silicon or nickel, and a resin such asPMMA (polymethyl methacrylate) or PDMS (polydimethyl siloxane) is moldedso that a lot of chips can be created at a low rate. In this case, it isnecessary to coat the resin so that the resin does not react with theorganic solvent. Moreover, not only the dry etching but also wet etchingmay be used as the etching of silicon and glass.

[0096] The first layer chip 51 is formed with an inlet 51 a forsupplying an exhaust gas sample containing dioxin or the like, an inlet51 b for supplying the water, an inlet 51 c and a channel 20 forsupplying the organic solvent, a through hole 51 f, a discharge port 51d for discharging unnecessary water and a discharge port 51 e fordischarging refined dioxin.

[0097] The second layer chip 52 is formed with channels 52 s and 52 t inwhich the exhaust gas sample and the water supplied from the inlet 51 aand 51 b flow and interflow, a porous glass 52 f for collecting andcondensing dioxin, and the channel 30 in which the collected andcondensed dioxin solution flows.

[0098] The third layer to tenth layer chips 53 to 60 are provided with asuitable reagent based on, for instance, Japanese Industrial Standards(JIS) in order to refine the dioxin using multi-layer silicachromatography. Namely, pursuant to the JIS, 53 g of sodium sulfate iscontained in the third layer chip 53, 54 g of 10 weight % silver nitrateis contained in the fourth layer chip 54, 55 g of silica gel iscontained in the fifth layer chip 55, 56 g of 22 weight % silica gelsulfate is contained in the sixth layer chip 56, 57 g of 44% by weightsilica gel sulfate is contained in the seventh layer chip 57, 58 g ofsilica gel is contained in the eighth layer chip 58, 59 g of 2% byweight silica gel potassium hydroxide is contained in the ninth layerchip 59, and 60 g of silica gel is contained in the tenth layer chip 60.Of course, the reagents may be altered in accordance with the otherstandards.

[0099] As shown in FIGS. 6 and 10, the exhaust gas sample and the waterwhich have passed cylindrical filter paper are supplied to the inlets 51a and 51 b of the pretreatment assembly 50 and pass through the channels52 s and 52 t so as to be mixed (#1). The cylindrical filter paper isbroken and the dioxin may be collected (#8) by soxhlet extraction usinga solvent instead of water.

[0100] The mixed solution of the dioxin and water passes through theporous glass 52 f, so that the dioxin is collected and condensed (#2).Namely, water vapor, carbon dioxide and nitrogen dioxide pass from theporous glass 52 f through the through hole 51 f of the chip 51 so as tobe discharged.

[0101] The water which contains the condensed dioxin or the like flowsin the channel 30. The organic solvent is supplied from the inlet 51 cso as to flow in the channel 20. The organic solvent contains hexane,toluene, acetone, dichloromethane and HCL in at the suitable rate. Thewater containing the dioxin or the like and the organic solvent passthrough the divided channel 32 so as to meet in the laminar flow mixingsection 36, and as mentioned above, the dioxin or the like isincorporated into the organic solvent (#3 in FIG. 10), so that the waterand the organic solvent are separated in the divided channel 40 (#4 inFIG. 10).

[0102] The unnecessary water is discharged from the upper discharge port51 d.

[0103] The organic solvent flows in the lower section and passessequentially through the chips 53 to 60 provided with 53 g to 60 g ofreagents and slightly mixed water is removed so that the dioxin isrefined (#5 in FIG. 10). The refined dioxin is discharged from the upperoutlet 51 e and is measured by GC/MS (gas chromatography/massspectrograph).

[0104] A second embodiment of the present invention will be explainedbelow with reference to FIGS. 7, 8 and 10.

[0105] In the second embodiment, as shown by a reference numeral 90 inFIG. 10, instead that after the water and the organic solvent are mixedby the laminar flow, they are separated (#3 and #4), as shown by areference numeral 92, turbulence occurs so that the water and theorganic solvent are mixed and thereafter separated (#6 and #7).

[0106] The pretreatment assembly 70 to which the present invention isapplied uses chips 71, 72 and 73 shown in FIG. 7 instead of the chips 51and 52 shown in FIG. 5. The chips 71, 72 and 73 can be processed by thesimilar method to the chips 51 and 52.

[0107] Similarly to the chip 51 of the first embodiment, the first layerchip 71 is formed with an inlet 71 a for supplying an exhaust gassample, an inlet 71 b for supplying water, an inlet 71 c for supplyingan organic solvent, a through hole 71 f and a discharge port 71 d fordischarging unnecessary water.

[0108] Similarly to the chip 52 of the first embodiment, the third layerchip 73 is provided with channels 73 s and 73 t in which the exhaust gassample and the water flow and interflow, and a porous glass 73 f forcollecting and condensing the dioxin.

[0109] Differently from the first embodiment, mixing spaces 74 formixing the water containing the dioxin or the like and the organicsolvent using turbulence are formed respectively between the first tothird layer chips 71 to 73. Moreover, a PZT layer 71 e is formed in anarea opposed to the mixing spaces 74 on the upper surface of the firstlayer chip 71. The PZT layer 71 e is divided into four sections, forexample, and a voltage of suitable waveform is applied to the respectivesections in a suitable order so that an ultrasonic is generated. As aresult, eddy is generated in the mixing spaces 74, so that the watercontaining the dioxin or the like and the organic solvent can beagitated and mixed.

[0110] The mixed water and organic solvent passes from the mixing spaces74 through a channel 75 formed on the third layer chip 73, so that thewater and the organic solvent are separated.

[0111] As shown in FIG. 8, microstructure 76 is formed in the lowersection of the channel 75 (namely, a first space). The microstructure 76has a plurality of columns having a diameter of several μm to severaldozen μm, and they extend from a bottom section 75 a of the channel 75to the middle of the height direction of the channel 75, and there is noobstruction in the upper section of the channel 75 (namely, a secondspace). A distance (gap) between the columns is, for example, not morethan 10 μm. The microstructure 76 are not limited to in the form of thecolumns, and may be, for example, prisms or cones. Furthermore, themicrostructure 76 may be made of a porous substance or a fiber block.

[0112] The surfaces of the microstructures 76 undergo a water-repellenttreatment. In the case where the microstructures 76 are formed by an ICPapparatus, since the working process uses C₄F₈ gas, their surfacesundergo water-repellent process without special additional treatment.The surfaces may undergo the water-repellent treatment by adheringfluorine macromolecules to the surfaces by eutectoid plating or thelike.

[0113] The water of the mixed solution which has entered themicrostructures 76 moves to the upper section of the channel 75 due tothe water-repellent treatment of the microstructures 76. Meanwhile, theorganic solvent just flows in the lower section of the channel 75.Moreover, the water and the organic solvent are separated to the uppersection and the lower section of the channel 75 with the assistance of adifference in specific gravity. The microstructures 76 may be formed inthe upper section of the channel 75 according to a difference inspecific gravity.

[0114] Thereafter, unnecessary water is sucked from a lower stream endsection 75 b of the channel 75 to the upper section as shown by an arrow77. Meanwhile, the organic solvent is sucked from a discharge port 75 cformed on the bottom face of the lower stream end section 75 b to thelower section as shown by an arrow 78 so as to flow into a refiningsection, not shown, (for example, it is composed similarly to the chips53 to 60).

[0115] As explained above, the flow of the laminar flow and thediffusion phenomenon of particles in the microarea are used, so that thedioxin can be extracted efficiently using a very small amount of asample. Moreover, a second liquid can be separated from mixed firstliquid and second liquid in the microarea.

[0116] Therefore, since the treatment can be carried out in themicrochips having a size of several cm×several cm, portableness isexcellent, and the treatment can be executed immediately anywhere, sothat the immediacy of the check is improved. Moreover, the reacting timeis fast and the treatment time is shortened, so that the cost can bereduced greatly. Further, since an amount of the organic solvent to beused for the extraction is greatly smaller than conventional methods,the method of the present invention is environmental friendly. Since thechip can be mass produced by utilizing a semiconductor process or thelike, the unit price is very low. Since the unit price of the chip islow, the chip can be disposable. When the chip is disposable, unlike inthe case where the chip is used plural times, the problem of pollutiondue to waste water does not arise and troublesome cleaning is notrequired.

[0117] The present invention is not limited to the above embodiments,and the invention can be carried out in another various forms.

[0118] For example as shown in FIG. 9, a partition wall 80 of thedivided channel 10 b is charged positively or negatively, so that thewater and the organic solvent can be separated. As for the partitionwall 80, main body sections 82 are formed by an insulating substance,and electrodes 83 a and 83 b are provided on side faces of the main bodysections 82 opposed to the channels 15 a to 15 g, so that outermostlayers 84 are covered with the insulating substance. For example, SiO₂or the like is deposited as an insulating film on the surfaces of theelectrodes 83 a and 83 b. The electrodes 83 a and 83 b are connectedwith a power source 85 so as to be charged positively or negatively. Atthis time, as shown in the diagram, the electrodes 83 a and 83 b whichare countered to each other via the channels 15 a to 15 g have the samepotential, so that the channels 15 a to 15 g are charged positively ornegatively in an alternate manner.

[0119] Since water is polar molecule and is always charged positively,it does not enter an area charged positively. In order that the water iseasily influenced by electric charge, the width of the channels 15 a to15 g is not more than 50 μm. Not more than 10 μm is preferable.

[0120] Further, the present invention can be applied not only to thepretreatment for the measurement of dioxin but also to a wide range. Ifthe present invention is applied, in the case where an organic substancewhich dissolves or flows in water is extracted, a slight amount of asample solution and an extracting solvent are mixed and the extractingsolvent containing the organic substance can be selectively extracted.

[0121] Although the present invention has been fully described by way ofexamples with reference to the accompanying drawings, it is to be notedthat various changes and modifications will be apparent to those skilledin the art. Therefore, unless otherwise such changes and modificationsdepart from the scope of the present invention, they should be construedas being included therein.

What is claimed is:
 1. An extracting method for incorporating asubstance contained in a first liquid into a second liquid, said methodcomprising the steps of: (a) transferring the first liquid and thesecond liquid in a channel so that the first liquid and the secondliquid alternately come in contact with each other respectively in notless than one or two laminar state, and the substance in the firstlaminar flow of the first liquid is moved to the second laminar flow ofthe second liquid; and (b) separating the second liquid from the firstliquid in a lower stream side of the channel.
 2. The extracting methodaccording to claim 1, wherein, in the step (a), the substance in theliquid diffuses voluntarily.
 3. The extracting method according to claim1, wherein the substance is dioxin, and wherein the first liquid andsecond liquid are water and an organic solvent, respectively.
 4. Theextracting method according to claim 1, wherein a flow velocity of thefirst laminar flow is equal to a flow velocity of the second laminarflow.
 5. The extracting method according to claim 1, wherein, in thestep (a), the first liquid and the second liquid are stopped in themiddle of the channel.
 6. The extracting method according to claim 1,wherein a width of each laminar flow is not more than 50 μm.
 7. Theextracting method according to claim 1, wherein the step (b) includesthe step of: (b-1) branching, in the lower stream side of the channel,the first laminar flow and the second laminar flow into a first branchchannel and a second branch channel, respectively.
 8. The extractingmethod according to claim 7, wherein the step (b) forther includes thestep of: (b-2) charging a vicinity of an inlet of the first branchchannel or the second branch channel. 9 A separating method forseparating a second liquid from mixture of a first liquid and the secondliquid, said separating method comprising the steps of: (a) allowing themixture to flow into the channel that is composed of a first space and asecond space, wherein the first space is provided with a microstructureso that one of the first liquid and the second liquid easily flowsrelatively, and wherein the second space extends along the first spaceand is connected with the first space; and (b) collecting the secondliquid is collected in a lower stream side of the first space or thesecond space in which the second liquid flows.
 10. The separating methodaccording to claim 9, wherein the microstructure is undergone one of ahydrophilic treatment and a water-repellent treatment.
 11. Theseparating method according to claim 9, wherein the microstructure isprovided with a functional group.
 12. The separating method according toclaim 9, wherein the microstructure comprises a plurality of elements.13. The separating method according to claim 12, wherein a distancebetween the adjacent elements is not more than 10 μm.
 14. The separatingmethod according to claim 12, wherein each of the element has acolumn-shape.
 15. The separating method according to claim 9, whereinthe microstructure is made of one of a porous substance and a fiberblock.
 16. An extracting structure for incorporating a substancecontained in a first liquid into a second liquid, said extractingstructure comprising: a channel for allowing the first liquid and thesecond liquid to flow therein in a form of a layered flow in which atleast one first laminar flow of the first liquid and at least one secondlaminar flow of the second liquid alternately come in contact with eachother, wherein the substance in the first laminar flow of the firstliquid moves to the second laminar flow of the second liquid through atleast one boundary between the at least one first laminar flow and theat least one second laminar flow; and a separating section, connected toa lower stream side of the channel, for separating the second liquidfrom the first liquid.
 17. The extracting structure according to claim16, wherein the substance is dioxin, and wherein the first liquid andthe second liquid are water and an organic solvent, respectively. 18.The extracting structure according to claim 16, wherein a width of eachof the at least one first laminar flow and the at least one secondlaminar flow is not more than 50 μm.
 19. The extracting structureaccording to claim 16, wherein the separating section includes a firstbranch channel in which the first laminar flow flows, and a secondbranch channel in which the second laminar flow flows.
 21. Theextracting apparatus according to claim 19, wherein the separatingsection further includes an electrode for charging a vicinity of aninlet of the first branch channel or the second branch channel.
 22. Anextracting apparatus comprising the extracting structure according toclaim
 16. 23. An extracting apparatus according to claim 22, wherein aflow velocity of the at least one first laminar flow is equal to a flowvelocity of the at least one second laminar flow.
 24. An extractingapparatus according to claim 22, wherein the separating sectioncomprises an electrode for charging a vicinity of an inlet of the firstbranch channel or the second branch channel, and wherein said extractingapparatus further comprises an power source for applying a voltage tothe electrode.
 25. A chip comprising the extracting structure accordingto claim
 16. 26. A separating structure for separating a second liquidfrom the mixture of a first liquid and the second liquid, saidseparating structure comprising: a first space provided with amicrostructure through which one of the first liquid and the secondliquid easily flows relatively; a second space extending along the firstspace and being connected to the first space; and a discharge port,connected to a lower stream side of one of the first space and thesecond space where the second liquid flows, for collecting the secondliquid flows therein.
 27. The separating structure according to claim26, wherein the microstructure is undergone one of a hydrophilictreatment and a water-repellent treatment.
 28. The separating structureaccording to claim 26, wherein the microstructure is provided with afunctional group.
 29. The separating structure according to claim 26,wherein the microstructure comprises a plurality of elements.
 30. Theseparating structure according to claim 29, wherein a distance betweenthe adjacent elements is not more than 10 μm.
 31. The separatingstructure according to claim 29, wherein each of the element has acolumn-shape.
 32. The separating structure according to claim 26,wherein the microstructure is made of one of a porous substance and afiber block.
 33. A separating apparatus comprising the separatingstructure according to claim
 26. 32. A chip comprising the separatingstructure according to claim 24.